RogueSheep is one of my favorite indie developers, and I thank them for sponsoring this week’s DF RSS feed to promote TouchUp, their new photo editing app for the iPad. It’s a recurring theme for me here at DF that pointer UIs (mouse or trackpad) are fundamentally different than touchscreen UIs. TouchUp gets it right. It doesn’t work like Photoshop or any other traditional pointer-based photo editing UI. It’s touch-based, from the ground up.

It’s a simple premise: each effect is a layer atop the original photo. Each effect can be “painted” by touch onto the photo. It doesn’t feel like any app I’ve used before, and it’s a lot of fun — and very easy to get started with. One example of TouchUp’s clever design: “brushes” are always roughly the size of your finger — you pinch-zoom the photo to adjust how big an area your brush affects, rather than changing the size of the brush. Check out the screenshots and demo videos at RogueSheep’s website to get a sense for how it works. Get it on the App Store for just $2.99.